Memory is one type of integrated circuitry, and is used in computer systems for storing data. Memory may be fabricated in one or more arrays of individual memory cells. Memory cells may be written to, or read from, using digit lines (which may also be referred to as bit lines, data lines, sense lines, or data/sense lines) and access lines (which may also be referred to as word lines). The digit lines may conductively interconnect memory cells along columns of the array, and the access lines may conductively interconnect memory cells along rows of the array. Each memory cell may be uniquely addressed through the combination of a digit line and an access line.
Memory cells may be volatile or non-volatile. Non-volatile memory cells can store data for extended periods of time including when the computer is turned off. Volatile memory dissipates and therefore requires being refreshed/rewritten, in many instances multiple times per second. Regardless, memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
A capacitor is one type of electronic component that may be used in a memory cell. A capacitor has two electrical conductors separated by electrically insulating material. Energy as an electric field may be electrostatically stored within such material. Depending on composition of the insulating material, that stored field be volatile or non-volatile. For example, a capacitor insulator including only SiO2 will be volatile. One type of non-volatile capacitor is a ferroelectric capacitor which has ferroelectric material as at least part of the insulating material. A memory cell incorporating a ferroelectric capacitor ideally is non-volatile due to bi-stable characteristics of the ferroelectric material that forms a part of the capacitor. Other programmable materials may be used as capacitor insulator materials to render capacitors non-volatile. Further and regardless, arrays of capacitors may be formed as part of an array of memory cells or an array in other integrated circuitry.
One manner of fabricating capacitors is to initially form an insulative or other support material within which one of the capacitor electrodes is formed. For example, an array of capacitor electrode openings for individual capacitors may be fabricated in an insulative support material, with an example material being silicon dioxide doped with one or both of phosphorus and boron. Openings within which some or all of the capacitors are formed are etched into the support material. Conductive material is deposited to line and less-than-fill the individual openings. The conductive material may be planarized or etched back relative to the support material to form individual elevationally inner capacitor electrodes within individual of the openings. In some methods, most if not all of the support material is then etched away to enable the radially outer sidewall surfaces as well as the radially inner sidewall surfaces of the electrodes to provide capacitor surface area and thereby increased capacitance for the capacitors being formed. Yet, capacitor electrodes formed in deep openings are often correspondingly much taller than they are wide. This can lead to toppling of the capacitor electrodes during etching to expose the outer sidewall surfaces, during transport of the substrate, during deposition of the capacitor insulator material, and/or during deposition of the outer capacitor electrode material. Brace or lattice-like retaining structures have been proposed and used to alleviate such toppling.